supplying different size modules with power

[Murdock]

Hey,

After recapping and cleaning I'm about to finaly use all my 24V modules I gathered over the last years.
But I'm not quite sure how I should approach the power distribution...

I have a big Monitora 24V psu and a DIN rack where I can put it in. I also got a Neumann 24V to 48V Eurocard which I also can put inside the DIN rack.

I would like to keep the 24V and Phantom power in seperate cables. For the Phantom I wanted to make "through" connections on the front of the rack. Something like 8 XLR in and out. So I can patch any mic into it and then to the preamp of my choice.
On the back I would like to have the 24V output connections.
How should I go about the connection to the modules? 
It would be easy and probably cheaper to just put like 16 XLR sockets in, but I'm hesitant, as they are not screw locked... And it's easy to plug audio cables in.
I thought about 3 pin Amphenol sockets but would like to hear your ideas.
Would it be better to have like 16 Amphenol plugs. Or should I use a long Multicore cable with only one connector on the PSU?
How do you guys get your power to your modules? 

I'm thankful for any tips and inspiration.

 

[Tubetec]

I think  Ian Bell has a section on good power wiring technique in his document repository ,have a look

If you really want screw lock connectors you could use an 'aviation plug' available with several pin configurations ,you could have a discrete cable for each module back to the powersupply if you wanted , but if your setting all your modules in a an enclosure maybe a single large diameter multiway cable might be ok .  You'll need a larger connector for the power supply end maybe an old 'video' 12 pin connector could be re purposed  ,an 8 pin 'speakon' can also be used ,of course you want it clearly labeled so no one ever plugs in a speaker into your psu

In your enclosure you could create buzz bars for the various rails and ground returns ,then put in suitable aviation plug and socket per module , remember to include enough pins for all your psu rails and a discrete earth return for power and chassis ,If you check the eurocard pinout on your modules ,you can count the number of wires you need ,so +24volts ,power ground ,chassis /signal ground,phantom power ,phantom ground etc

Theres a couple of sizes of aviation plug also ,even the very small ones would be adequate for your modules. Come up with a wiring convention for the plugs so it allows compatibillity across all the modules ,how will the audio signals be carried in and out of your rack ?
Will  you use edge connectors to connect to the modules ? it'll make life much easier , a single 8 pin speakon on the psu and rack with nice fat cable will do ,then on the inside of the rack wire from the speakon socket to the individual edge connectors , if you need you  could find a lot of the connections or even a special racks with edge connectors /looms cheap at Bjorns OD&D in Holland.

 

[Murdock]

Hey,

thanks for the answer and suggestions.
I already thought about using those aviation plugs. There are even 2 pin connectors. Thanks for reminding me. Seems to be a good solution as they are also cheap.

I will probably put each module type into their own case as they are different size. So each has to have it's own power connector...

But you reminded me of another question...
How about the grounding inside the power supply rack?
The 0V from the 24V supply is also connected to the 0V rail of the 48V card as it gets it's supply voltage from it.
So would it be the correct way, to have a bus bar for all 0V connections on the aviation plugs going to the supply and then from there to the star ground/chassis next to the IEC inlet?

What about power supply cable? Does it make sense to use normal "balanced" cables? Using the two conductors for 24V and 0V and the shield as ground connection?

Also, I'm a bit concerned about the phantom power... I read about the problem with phantom power and high step up transformers and that I should use ramped phantom power. I can't really see on the schematic if it is ramped or not. Can somebody maybe have a look and tell me?

 

[Tubetec]

Maybe give the rack  its own discrete connection back to the supply  through to a point close to chassis or safety ground in the psu.
I think the two pin plugs and balanced screened mic cable is a good plan,you can terminate the screen of the  individual psu cables back only at the end it connects to the buss bars ,then in your plug screen remains unconnected ,only black(gnd) and red(24v+) are on pins one and two of the connector .

The thing is all your modules are edge connectors, do you intend to solder directly to these pins to attach your cables ?, or will the connector go onto the modules itself ? 

If you got yourself some of the correct edge connectors for your modules you'd be a lot better off ,you can simply make up a small wiring loom ,from the buss bars near the psu to the back of the each edge connector ,then tie everything up with cable ties, your audio ins/outs the same,ins wired to xlr and outs on jacks if you like . having to drill and mount all the aviation plugs is going to take ages ,your just making work for no reason .

Try looking here you might find something cheap with the right edge connectors , and it might only require a small amount of work to get it running . If there is different kinds of card/edge connector that can be accomodated too ,just modify the mounting bracket to suit ,Bjorn at OD&D has tons of old European broadcast gear and all the connectors you need.

https://www.ebay.co.uk/str/Outlaw-recording-and-pa-equipment/Racks/_i.html?_storecat=8189182011

 

[Murdock]

I didn't get everything you wrote.
Wouldn't it be  good to use the 2 pin connectors for 0V and 24V and connect the screen of the cable on each end to the connector housing?

I have all the edge connectors for the modules.
Thanks for all the suggestions.
But I plan to build each pair of modules in their own wooden box. But with aluminium backpanels with XLR and power sockets.
Sure, it would be easier and cheaper to just make some wire looms like you said.
But it's not very mobile and also quite cluttering having around 16 modules loose in the studio... Also I probably want to add some features to the modules like hard bypass for the EQ's or phase flip for the preamps.